Home Secretary Jacqui Smith has rejected calls for Metropolitan Police Commissioner Sir Ian Blair to resign.
The force broke health and safety laws when officers shot dead innocent Brazilian Jean Charles de Menezes in 2005, a court found on Thursday.
Tory and Lib Dem politicians said Sir Ian should take responsibility for the Metropolitan Police's failures.
But Ms Smith reiterated that she had "full confidence" in his ability and his officers to protect Londoners.
She said her heart went out to the family of Mr de Menezes, who was mistaken by police for a suicide bomber.
But she added that it was important to remember that when the Brazilian was killed, the Met was operating against the backdrop of the 7 July bombings in London and in the immediate aftermath of the attempted 21 July attacks.
Ms Smith said: "Day in day out, Sir Ian and the Metropolitan Police and police officers across this country help to keep people safe from terrorism, and I think that my job and that of other responsible politicians is to support those people who are risking their lives to keep this country safe from terrorism."
Just two weeks before Mr de Menezes's shooting, 52 people had been killed on London's transport network as a result of terrorist attacks, she added.
"That's the context of this case," Ms Smith said.
"And in that context of the serious threat that we face, I have full confidence in the Metropolitan Police and their Commissioner to continue the fight against the serious terrorist threat that we are facing.''
On 22 July 2005, Met officers pursued Mr de Menezes to a Tube station and shot him seven times, mistaking him for a terror suspect.
The force broke health and safety laws during the operation, a jury found.
Mr Menezes was mistaken for a suicide bomber
Immediately after the verdict, Sir Ian announced he would remain in the job and was backed by the prime minister.
But Labour MP Kate Hoey, whose Vauxhall constituency covers Stockwell Underground station, said Sir Ian should step down to restore confidence in the policing of London.
She said "he should go and accept responsibility" if confidence were to be restored "for the ordinary policemen and women".
Earlier, opposition politicians led calls for Sir Ian to step down.
'Series of accidents'
"It was a horrific series of mistakes and he is the person responsible," said shadow attorney general Dominic Grieve.
He added that the whole incident was "rather shameful in terms of the competence of the police, that an innocent person should be shot in that fashion, when in fact there was a series of accidents that led up to it, which shouldn't have occurred".
Meanwhile, the family of Mr de Menezes in Brazil have said that the police must pay for their mistake.
Mr de Menezes's brother, Giovanni da Silva, told the BBC he was pleased with the outcome of the case but described it as just the start of the family's campaign for justice.
Officer in command
During the trial, an Old Bailey jury heard that Scotland Yard commanders had made a string of errors on 22 July 2005 that culminated in an unwarranted risk to the public and ultimately the death of Mr de Menezes.
Mr Justice Henriques described it as "an isolated breach brought about by quite extraordinary circumstances".
"One person died and many others were placed in potential danger," he said.
Mayor of London Ken Livingstone said the health and safety verdict made it more difficult for police to protect the capital against terrorism.
He backed Sir Ian, describing him as "an incredibly talented officer" who had modernised and driven change through the Met, and had also brought down crime.
He added that the jury said the officer in command, Cressida Dick, bore no responsibility.
"So the idea that people farther up the food chain somehow bear that responsibility is nonsense."
Richard Clayton QC, who specialises in bringing cases against the police, told the BBC that forces must be subject to the law and said he doubted that officers would be deterred from doing their jobs.
He added: "My guess is that common sense will mean that actions aren't brought because everyone knows the difficulties under which the police labour and I think it's important not to lose sight of that."
A report into the shooting by the Independent Police Complaints Commission (IPCC) is expected soon and an inquest is also to take place.